Pratt & Whitney published the following Media Statement on PW1100G-JM Engine:

Pratt & Whitney, with the support of Airbus, is in close contact with customers to address the results of a recent finding related to the knife edge seal in the High-Pressure Compressor (HPC) aft hub on the PW1100G-JM engine powering the A320neo. This issue is isolated to a limited subpopulation of engines.

We have identified the potentially affected engines and communicated with our customers. As a precaution, aircraft with these engines will be addressed in a manner consistent with the operational instructions issued by Airbus and coordinated between Airbus and Pratt & Whitney as needed.

Since entering service in January 2016, these engines have more than 500,000 hours of passenger service. The GTF engine has demonstrated its promised ability to reduce fuel burn by 16 percent to reduce nitrogen oxide emissions by 50 percent to the regulatory standard and to lower the noise footprint by 75 percent.